Conventionally, the Universal Serial Bus (USB) standard has been widely used as a standard for connecting, to an electronic apparatus such as a smartphone, external peripheral equipment such as an alternating current (AC) adapter. According to a USB interface in which the USB standard is used, a device ordinarily includes an overcurrent protection mechanism on a host-side therein as measures to protect the device from an overcurrent which is caused by, for example, an unexpected short circuit of a power supply.
However, in the market, there are (i) USB hosts in which no overcurrent protection mechanisms are included and (ii) USB cables in which wiring errors are made. Therefore, techniques are being developed to notify a user in a case where an overcurrent flows as a result of using such a USB host and such a USB cable.
Patent Literature 1, for example, discloses a USB device which includes an overcurrent preventing section, an overcurrent state detecting section, and an overcurrent state notifying section that are provided for signal lines and electric power lines. The USB device makes it possible to notify a user of an abnormal connection state with use of the overcurrent state detecting section and the overcurrent state notifying section even in a case where, for example, USB cables with wiring errors are used.